The Alternate Universe Paradox
by the-WYSIWYG-type
Summary: Penny Cuoco is a lot of awful, terrible, completely true things. But she is not indecisive and more than anything, she wants Doctor Sheldon Lee Cooper, she just doesn't completely comprehend why yet...AU. Shenny
1. Chapter 1

**Title:** The Alternate Universe Paradox  
**Summary:** Penny Cuoco is a lot of awful, terrible, completely true things. But she is not indecisive and more than anything, she wants Doctor Sheldon Lee Cooper, she just doesn't completely comprehend why yet...AU. Shenny  
**Rating:** M  
**Disclaimer:** I do not own Big Bang Theory or the pairings would be Penny and Sheldon/Amy and Leonard, not the other way around.

**Chapter 1 Song ****_Pairing_**  
_"Migraine"_ by Twenty One Pilots (Listen to it like you're Sheldon)

Doctor Sheldon Lee Cooper had spent nearly every moment of the past 7 years wondering what had possessed him to become a University Professor. Before he had even considered the possibility of teaching he had known that the world of academia had become a cesspool of inflated egos with slightly above average intelligence individuals flinging their seemingly drug-induced theories and postulations at other individuals dumb enough to think them potentially valid. Perhaps Sheldon had taken on a persona of self-righteousness when he'd taken the position, believing he alone could sanitize the infection the undeserving primates had laid before him. And what better way of doing it then by cultivating the minds of the future physicists, microbiologists, and (Sheldon shuttered to think) engineers?

But today was truly straining the extent of his God Complex. Because today he was beginning a new semester with new students and one of which was severely late. He had spent half an hour breaking the expectations of every student in the room, another half hour giving a detailed description of the next few weeks, and the last hour attempting to make String Theory remedial enough for them to attempt to understand it and that last student had yet to have the nerve to show up. Not that he expected the student in question to understand a single word he had said if she'd bothered to show up based on the name on his roster.

_Penelope_ _Cuoco_, Dr. Cooper thought. _With a name like that she would probably fit in better with the Performing Arts and Humanities branches of the University._

Dr. Sheldon Cooper felt himself smirk lightly at his own joke as he continued scribbling away on his whiteboard, the Higgs Boson particle at the center of his scribbling. It seemed only a few minutes when his concentration was interrupted by the door to his classroom lightly scrapping the floor. Sheldon sighed, he had told administration multiple times that the door was set unevenly in the frame and that the scrapping was enough to drive any rational person insane, but they just chose to ignore his complaint multiple times over.

"Doctor Sheldon Cooper?" he heard a small voice ask behind him and the door scrapped shut again.

Sheldon sighed once more, not willing to break his concentration on the ever expanding problem in front of him by looking at the visitor.

"If the plaque on the door is an indication and the obvious elimination of yourself as the potential candidate, then I believe it would be safe to assume that I am indeed Doctor Sheldon Cooper."

He heard the woman behind him chuckle.

"I see," She said, "and based on your response and the equations on your board, then I believe it would be safe to assume that you're one of those 'Beautiful Mind' geniuses as well."

Sheldon turned quickly, completely caught off guard by the woman's quick witted comment only to find himself caught off guard by what he saw. Remaining completely objective, she was quite the sight. Long, heavy golden curls clung drunkenly to her shoulders and ample breasts for support. Her eyes were a deep green reminiscent of the ever seeing and scrutinizing eyes of feline predators. Using the door frame as a reference he could tell that she was easily 5 foot 6 inches, perhaps 5 foot 7 and only 120 pounds soaking wet and with bricks in her snuggly fitting jean pockets. She was smiling softly at him, a battered Calculus book and scientific journal resting precariously against her wide, childbearing hips like a small toddler. It took Sheldon a moment to come back into himself long enough to respond.

"I'm going to make the presumption that you are Miss Penelope Cuoco."

"Most people just call me Penny." She said nonchalantly as she set her books down on a nearby desk.

"I am not most people," Dr. Cooper corrected, "And I hate to be the individual to point out the painstakingly obvious, but you are three hours, twenty three minutes, and thirteen seconds late for Introduction to Theoretical Physics. You are welcome to join myself and the rest of the class at one thirty tomorrow afternoon."

Penny sighed as Dr. Cooper quickly packed his messenger bag and made his way to the classroom door, obviously no longer interested in the problem on the board. She stood to leave as well, following him down the university hallway to the parking lot.

"Doctor Cooper, I do apologize for my absence earlier. My car was having trouble starting and I had to improvise."

Sheldon scuffed as they continued to walk.

"Miss Cuoco, as much as I may appreciate your eagerness to appeal to my better nature I should advise you that I do not **have** a better nature. Your ability to arrive to class in a timely fashion does not affect me in any way, shape, or form. And by following that vein of thought, I could not care any less about your apology."

Penny threw Sheldon a nasty look before hurrying away and jumping into her car nearby. If the manner in which she sped away was any constellation, Dr. Sheldon Cooper was fairly certain that he would not be seeing her again (not that he really cared in the first place).

Sheldon Cooper couldn't have been more wrong when he believed that Penelope's driving off in anger would be the last that he would see of her. As luck (if he believed in such hokum) would have it, his neighbor directly above him had decided to move out not too long ago, much to his pleasure. For the past 2 weeks, the noise overhead had been pleasantly nonexistent and he had been dreading the day when his landlord would be capable of filling the vacancy. As he entered the lobby to his apartment complex, his stomach turned; it was filled with moving boxes, miscellaneous appliances, and a lightly used mattress. Sheldon couldn't help himself when he followed his desire to run up the 4 flights of stairs to apartment 5A to make sure that what he was assuming was correct.

As soon as he made it past the fifth floor landing and saw the apartment door open, a couch sitting in the middle of the open room, Sheldon let loose a sigh of defeat. And when he saw the alluring curvature of a woman, a woman who looked surprisingly like his previously missing student, he couldn't help the words that came tumbling out.

"You're doing this deliberately, aren't you?"

He watched transfixed as Penny turned, the blonde of her hair shining gold in the light that flooded in from the window and the setting sun.

"I'm sorry?" She replied as realization dawned on her as to who she was speaking to.

"You were anger with me and out of that anger must have devised this plot to live directly above my own apartment to further torment me."

Penny's face morphed into a type of confusion.

"Doctor Cooper, I'm not that vindictive. I was looking for a new apartment and came across this one a few days back. I had no idea that you lived in this building until just now."

Penny turned away as she placed a handful of wine glasses into a cabinet before heading out of the apartment to make her way down the stairs, Sheldon following close behind her.

"Since you appear to be making yourself comfortable, there are a few requirements that I need to go over with you…"

"Requirements?" Penny squeaked, "What are you, my landlord?"

"Of course not," Sheldon said, "And that brings me to the first requirement, please refrain from idiotic and unnecessary questions and-slash-or statements whenever we are in immediate proximity of one another. I am your professor and, as of this moment, your neighbor, not your friend. Second requirement, please refrain from any whistling, stomping, instrument playing, or all around ruckus inducing behavior at all times. The tenants prior to you were freakishly feline with their silence. Lastly, get an area rug."

At his final statement, Sheldon stalked off and made his way back to his apartment where he locked himself away before Penny could object. And, in all honesty, Penny wasn't in the mood to object (she had kind of skipped his class earlier that afternoon).

Penny wasn't spectacularly bright, that much was obvious when you took one look at her. She hated the stereotype of the "dumb blonde," but she'd be a fool to believe that stereotype didn't pertain to her in some fashion. Shoes, she understood. Celebrities, she got. Science, that was a bit of a grey area to her. Yet, without fail she had made an appearance to Dr. Sheldon Cooper's Introduction to Theoretical Physics class every day over the course of the past three weeks. There was something to his madness, something to his enthusiasm and love for the field that shined through his lectures and his biting retorts that compelled her to sit and listen, even if she had only the vaguest idea as to what he was saying.

It was on day number 23 that he had approached her.

The class had been dismissed already, but Penny was still trying to scribble down the still fairly incoherent symbols sprawled across the whiteboard. Dr. Cooper had made it readily apparent that there would be an exam by the end of the week and Penny was nowhere near ready, but if there was one thing that growing up in Nebraska had taught her, it was to never admit defeat, even when that defeat appeared imminent. It was as she was scribbling another lambda into her notebook that she saw her professor approaching her.

"Why are you still here, Miss Cuoco?" he asked, "Class was dismissed nearly fifteen minutes ago."

Penny looked up at Dr. Cooper, confused by his question. He could obviously see her notebook and the fact that what was written in it was a mimicry of what was on the board.

"I'm finishing my notes, Doctor Cooper."

"Why?"

Penny knitted her eyebrows together at the seemingly pointless question.

"We have an exam on Friday. I want to make sure that I'm ready."

Dr. Cooper scuffed at her before going to erase the board, much to Penny's anger.

"The exam is only over the more remedial subjects of theoretical physics. Basic differentials, Newtonian mechanics, and perhaps a little bit of work involving the Calculus of Variations. If you're incapable of understanding the more basic aspects of the field, then perhaps you should look into obtaining a new major."

Sheldon placed the dry eraser down, the board now pristine and clear.

"This is the only course I'm taking at the moment. I have no major."

Sheldon looked up at the dirty blonde, her brilliant emerald eyes piercing through him as she kept her expression neutral.

"Then why are you even here?" Sheldon asked abruptly.

Penny shrugged, "I don't know," She admitted, "Out of curiosity, to keep the boredom at bay, to spice things up, whichever answer suits you best."

Penny stood and gathered her things, ready to get out of the far too large classroom and away from her professor's far too personal questions and seething statements.

"I will see you tomorrow, Doctor Cooper."

Sheldon had begun to speak before Penny's hand had even touched the cool metal of the doorknob.

"Miss Cuoco," Sheldon blurted out, "If you believe that you need more practice before the exam, I would be willing to allocate a generous amount of time to insure that you fully understand the material by Friday."

Penny stood still for a moment, mulling over what was just said.

"Are you offering to tutor me, sir?" She asked as she turned around to face him, her expression leery.

"Why yes, it appears I am."

Penny flashed her teacher a brilliant smile, the happiness shining in her eyes.

"I would be delighted if you could do that, sir. My apartment would be best in terms of studying. You know where I live, Doctor Cooper."

And with that, Penny left the classroom, the scrapping of the door causing Sheldon to wonder exactly why he had offered to help her at all (what was wrong with him?).

Sheldon was a very punctual individual, as Penny learned fairly quickly. At 6pm on the nose every night Sheldon would knock on her door in triplicate. He would make his way in, a giant transportable whiteboard in hand as well as a half dozen composition notebooks and various worksheets. By the time Thursday night had rolled around, Penny felt as much prepared for the Exam as she had on Tuesday, but she wouldn't let it discourage her. No matter how much she wanted to simply quit, she couldn't bring herself to do it in the presence of Dr. Sheldon Cooper.

"Now, based off of this equation, what would you be able to deduce in regards to the object's mass?"

Penny stumbled as she attempted to formulate the correct answer.

"That the object's mass is…directly linked to…its gravitational pull?"

"Are you asking me or telling me, Miss Cuoco?"

"Telling you?"

Sheldon sighed, "Thank goodness this is a written exam and not an oral presentation."

"So, was that answer correct?" Penny asked hopefully.

"Yes," Dr. Cooper conceded, "That answer was indeed correct although unnecessarily apprehensive."

Sheldon picked up the eraser and began clearing the board, ready to construct another problem for Penny to attempt to deduce.

"Miss Cuoco, you actually have a fairly decent grasp of the material. I believe that you may even have the capacity of securing a passing grade on the exam tomorrow."

Penny's eyes lit up as she stared at Sheldon's lean frame as he began writing a new equation on the board. His slender hands moved quickly as he placed incomprehensible formulas and doodles on the whiteboard in front of her.

"Do you honestly believe that, Doctor Cooper?" She asked.

"Why, certainly." He replied immediately, "I am not opposed to giving credit where it is appropriately do and you're dedication to learning the material, although fairly labored and surprisingly time consuming, has been intensely beneficial to your overall understanding of the field. You just need to come to the glaring realization that you're more knowledgeable than you think and be confident in your answers. You'll be closer to correct than incorrect almost every time."

It was a very abrupt impulse that caused Penny to bolt from her chair to hug her professor across the back. She could tell that Dr. Cooper was immediately put off by the physical contact (after all, she had heard the stories about the man so adverse to germs that he would grow his own bacterial cultures if he believed himself exposed to potential disease), but that did not hinder nor deter her. All she could feel was his warmth and his presence and an all-encompassing wave of happiness because, even if Dr. Cooper hadn't actually said it, he had hinted that perhaps she was making the right choice after all. Perhaps she wasn't just a dumb blonde covered in the scars of her drunken mistakes.

Perhaps there was hope for her yet.

"Thank you, Sheldon." Penny whispered, her smile buried deep within his back.

And although she couldn't see it or feel it, Penny was sure that there had been the ghost of a smile on Sheldon's lips as he provided her a very small "You're welcome Penny."

A/N: Hallow folks! This is theWYSIWYGtype. I hope you guys like my AU Shenny story. I got the idea during the episode where Penny had Sheldon tutor her so she could have conversations with Leonard about his work (the plot of the story itself, not just the idea of the tutoring thing, obviously). I started working on it when I had resigned from my previous job and was job hunting and actually got a few chapters together. I initially wanted to wait until I was completely done with the story before uploading the first chapter since I am notorious for not finishing things that I start, but I'm so attached to this story and I'm planning on making it only 10 chapters long max and I'm already halfway done with it, so I figured someone out there may actually really want to read a nice AU Shenny story.

Personal note, they may be a little OOC, especially in later chapters. I hate the idea of Penny being a typical "dumb blonde." Maybe I'm biased because some of the smartest people I know are what others would consider without knowing them "dumb blondes" and "Barbie dolls" and other ugly stereotypes. So, this story is more playing off the idea that Penny went through her "dumb blonde" stage and just got so fed up with being the pretty-face, no-brains type and sort of bettered herself for herself because being a stereotype wasn't helping her and that's where her side of the story picks up. It also picks up where Sheldon sort of gave up on string theory much sooner and the next option that he could perceive for a failed scientist which, to him, is teaching. So the story plays off of the idea of what if their lives hadn't collided on a personal level, but a professional level. I don't know. I think its an interesting concept, trying to balance business and pleasure, especially a business/pleasure relationship between a teacher and a student.

Also, I will be pairing each chapter up with a song that I feel best exemplifies the chapter or that I pulled inspiration from for a chapter. For this chapter the song is "Migraine" by Twenty One Pilots. Listen to it thinking in Sheldon's shoes, that's the best advice I can give you.

If you liked the story, please comment and follow. I'm hoping to get this story completed in the next month and just sort of rapidly update from now to October at the latest (finger crossed).


	2. Chapter 2

**Title:** The Alternate Universe Paradox  
S**ummary:** Penny Cuoco is a lot of awful, terrible, completely true things. But she is not indecisive and more than anything, she wants Doctor Sheldon Lee Cooper, she just doesn't completely comprehend why yet...AU. Shenny  
**Rating:** M  
**Disclaimer:** I do not own Big Bang Theory or the pairings would be Penny and Sheldon/Amy and Leonard, not the other way around.

**Chapter 2 Song ****_Pairing  
_**"Move on Me" by Fink

Dr. Cooper was indescribably nervous for Penny, but he was perplexed as to why. Ever since the night prior where Penelope had embraced him (completely uninvited, mind you) there had been an immediate shift in his emotions towards her. He could still feel the soft burn of her body heat as it soaked into his clothes, the light scent of her green apple shampoo, and the massaging motion of her lips as they moved to make words across his back. The experience hadn't been completely unpleasant and in the absence of his normal disgusted and uncomfortable response to unnecessary physical human contact, he had been consumed by an overwhelming yearning for her. Not a physical yearning, per say, but an emotional yearning for her presence and her well-being.

Dr. Cooper tensed as Penny got up from her seat and made her way to his desk, her first finished exam in hand. She smiled as she placed it gently before him and made her way out of the classroom, the crooked door lightly scraping on her way out. It took all of Sheldon's willpower not to simply tear through her exam, scrutinizing it to see exactly how she had done, but he somehow managed to look over every equation, taking his time as he marked off an answer here and an answer there, scribbling notes in the side margins as he often did. It wasn't until he had finished her paper and calculated out the math in his head that he discreetly let loose a small smile.

77.8%. C+. Not the most stellar of scores, but not too bad considering a month ago he wouldn't have even thought her capable of receiving a high failing mark (not that he believed in such nonsense). Sheldon felt a bizarre sense of accomplishment as he held her paper between his fingers. Perhaps this was the emotion that had persuaded him into becoming an educator and, perhaps it had taken teaching Penny for him to fully realize that fact.

-/-

Penny stood in her bedroom, fingering the feathered edge along the torn seam of her favorite silk dress. She had the dress for years, worn it more than probably any other article of clothing she possessed. But, she could concede that its untimely demise was perhaps for the best (it reminded her of too many bad memories and rubbed the still raw edges of recent scars). She held the dress to her chest, unsure of what to do with the fabric, unwilling to throw it out, but knowing that she could never wear it again; the fabric was far too thin and delicate to hope to repair and it had been such a snug fit before, even if she did find a seamstress capable of mending the seam, there was no guarantee that she would be able to fit it again.

Sighing, Penny laid the dress along her bed delicately before slipping on a skin tight, candy apple red dress with a sweetheart neckline and soft off the shoulder sleeves. Grabbing her keys, and throwing on her peep-toe stilettos, Penny made her way out of her apartment only to be stopped by a blushing Sheldon Cooper.

"Doctor Cooper," Penny began awkwardly, shifting slightly to put a little more distance between her and her professor.

"Is there something I can do for you?"

Sheldon shook his head, warmth spreading up from his neck to lightly tint his cheeks.

"Miss Cuoco," Sheldon said, "I came by to inform you of your exam score. You passed."

Penny's eyes went wide as she looked straight into Sheldon's deep baby blues.

"I passed?" she whispered, "But…not to sound ungrateful, did you…did you change some of my answers? I don't see how I could've passed without you either changing my answers or only grading a portion of my test."

Sheldon chuckled lightly.

"Oh, Miss Cuoco, I do not believe in dishonesty in any form. Especially in the world of academia. You passed of your own accord."

Penny's jade eyes bore into Sheldon's cobalt orbs as a smile erupted across her face, bathing her skin in its warm glow. Penny could feel it bubbling inside of her, that overwhelming compulsion she sometimes got to giggle when something ludicrous and silly managed to work out. She could feel the emotion building inside of her ready to burst and before she could stop herself she was bent over, trying to control the laughter that flooded her insides and was now gushing from her lips. After a moment, Penny composed herself enough to stand up straight and give her thanks to the man in front of her.

"That's the best news I've heard today." She smiled, "I was just heading out to go to a dinner party, but, you know what? This calls for a celebration!"

Penny was beside herself with enthusiasm, her hand grabbing Sheldon's as she dragged him down the stairs and towards the front lobby.

"Miss Cuoco," Sheldon intoned, "Where on the earth are you dragging me to? I'll have you know I have some very serious work to attend to."

Penny scuffed as she led the tall, lanky genius out of the lobby and into the apartment parking lot.

"First off, Doctor Cooper, you can just call me Penny and I'll just refer to you as Sheldon outside of the classroom. All of this 'Miss' and 'Doctor' stuff isn't necessary when we're just two adults out on the town. Secondly, you're work will still be there when you get back. Tonight, we're celebrating your amazing teaching skills and my amazing ability to be awesome."

Sheldon rolled his eyes as he was forced into the passenger seat of Penny's mustard yellow, lightly rusted subcompact car.

"Being awesome is neither a physical, emotional, nor psychological trait that can be measured by any modern or post-Mayan form of measurement."

Penny sighed as she drove from the apartments and to a local bar. Hopefully after a few drinks, her professor would be more agreeable.

-/-

Sheldon had never really cared for alcohol. From a young age, he'd grown to hate liquor; between his father's alcoholism and borderline abusive tendencies when he drank and his mother's absolute divine hatred of it, Sheldon quickly learned that his best choice of action when it came to wine and spirits was to just avoid them altogether.

Yet, as Sheldon Lee Cooper sat at his seat at a dark, dank bar next to a beautiful blonde, sipping something that tasted surprisingly like fresh cherry lemonade (although the bartender called it an Amaretto Sour), he couldn't help but think that perhaps he had been wrong all of these years about the hooch. After all, he was in no way his father and even less like his mother. He quite liked the way that the synapses in his brain slowed down and quieted the constant stream of thought that ran through his head. He enjoyed the way in which his phobias and ticks died down with the more he consumed. He liked the feeling of looking at Penny and all her curves and dips and being able to truly appreciate her beauty and laughter. These were things that alluded him in his sober state, things that he was never able to enjoy or even comprehend being a level-headed genius.

He liked feeling—dare he say it?—normal.

"So," Penny began, her fingers circling the rim of a glass of Jack and Coke, "is the great Sheldon Cooper currently involved in a relationship?"

This was another thing that Sheldon quite enjoyed about alcohol; Penny's bluntness and unabashed curiosity.

"No," Sheldon began, "I was once involved in an intellectual relationship with a neurobiologist. We had hashed out the idea that our DNA was the most genetically compatible to create a bloodline of mentally superior offspring. However, my disinterest in a sexual relationship with her was what ultimately ended it."

Sheldon took another large gulp of his drink as Penny looked at him sadly.

"Aw, sweetie, I'm sorry."

Sheldon eyed Penny weirdly.

"Don't be. She is currently engaged to an experimental physicist that I use to have a close working relationship with. From my understanding, she is much happier now than I could have ever made her."

Sheldon finished off his drink, ordering another before further addressing Penny.

"What about you Miss Penny Cuoco?" He began, "Surely a woman as attractive as yourself is involved in a coital relationship."

Penny adverted her eyes from Sheldon as she studied her half full glass (or, in this case, half empty).

"No," she said softly, "Not currently."

Penny smiled softly as she went on, "I use to be involved with a man and it was serious. But…I just…I couldn't be who he wanted me to be."

Penny took a deep swig of her drink, nearly polishing it off as she continued.

"I guess, sometimes, I find myself still trying to be what he wanted me to be. He was smart, like really smart, but not nearly as smart as yourself." Penny corrected as she noticed the raised eyebrow Sheldon pointed in her direction, "And he was beautiful in the way that smart people often are. He was sweet and kind, but I could never be good enough for him. I couldn't love him the way he wanted me to. I guess it ended for a similar reason your relationship did; I just couldn't bring myself to sully my hands with him."

Penny made a motion to stand as she finished her drink and grabbed her purse.

"It's late, Sheldon. We should head back."

Sheldon found himself nodding dumbly as he finished his drink and followed her out to her car.

There was another side effect to the alcohol, Sheldon realized as he stood and felt the weight of the liquor fully press against him. He found himself entranced by his student, taken by her beauty and the way that her dress hugged her frame and cradled her breasts. What was it about her that made him want to instinctively follow her every move? Made him want to watch her like a predatory cat hiding just out of camera shot, ready to pounce and devour her whole? It was a new feeling for him, an inspired feeling, and he had wondered why he had never felt this way about any other person previously.

Sheldon seated himself softly in the passenger seat of Penny's busted car and watched entranced as she turned the engine over and fiddled with the hand break to get it moving again.

Everything about her was so quaint, so coy and enticing. From the way her hair fell about her shoulders in soft curls to the way she smoothly parked her car and made her way to the apartment building. Sheldon felt like a moth, drawn to the overpowering flame of her presence, willing to burn himself alive to have just a taste of her overwhelming warmth.

It wasn't until she and Sheldon were facing his door that he snapped himself from his reverie enough to respond to her.

"Well, it was an experience Sheldon." She began, a soft smile on her face, "I'll see you later."

She made to walk away, but to Sheldon's confusion, she turned back to look at him, a surprised expression covering her face like a mask. Perhaps it was the alcohol or even the hour, but it seemed to take a painstakingly long moment for the nerves in his fingertips to communicate with the synapses in his brain and then convert that information into something that he understood. Looking down, Sheldon saw the peculiar sight of his hand on her wrist. 5 Mississippi's passed as his brain attempted to scream at him again to let her go, but his alien hand wouldn't budge.

"Sheldon?" Penny asked, as she turned to face him fully, "Why are you holding my wrist?"

Her words seemed to be the remedy for the spell his hand was under and he felt himself shrink away from her, his hand cradled close to his chest as if he had just been burned. The movement had been so abrupt, he felt himself wobble slightly off balance, his liquor addled brain unable to fully figure out how to realign himself without the help of the door frame.

"Sorry darlin'." Sheldon began, only to quickly zip his lip.

Penny's face broke into an intrigued smile as Sheldon tucked away another inconvenient fact of drinking; apparently liquor and his Southern dialect were not as mutually exclusive as he would have thought. Penny pushed past Sheldon, grabbing his key from his slender fingers and opening his apartment door.

"So, I'm going to assume, since I've never heard you speak with that accent and the way you're hugging your doorframe for dear life, that you are far more drunk than I had initially realized," Penny began, pushing Sheldon into his apartment.

"Here," she said, offering her arm for him to stable himself with, "I'll help you to bed. Where's your room?"

Sheldon's initial instinct was to advise her that no one was allowed in her room. Not even beautiful women wearing dangerously seductive outfits helping him into bed after he had drank too much at a bar (the whole scenario was really quite improbable before now, when he thought about it). However, his fogged brain wasn't willing to take that approach and instead he simply pointed down the hall as Penny accompanied him to his bedroom. He could feel the liquor really taking effect as the hall began to spin slightly.

How many drink had Sheldon put away? 4? 5? He was sure he hadn't had nearly the amount necessary to have his head swimming the way it was. And he certainly hadn't had as many as Penny who was sitting him on his bed and bustling about his bedroom like she'd had nothing but water all night. Penny…

Sheldon watched entranced as she moved about the room and he found his mind wandering to some of the baser urges of his sex. There were no equations in this part of his mind, no universal mysteries to try and solve. This part of his psyche was simply male and craved what every male craved as he focused on Penny's round buttocks as she knelt to help him out of his shoes.

He could imagine her standing in front of him, those beautiful blonde curls hanging heavy about her face as she smiled seductively at him, the zipper of her dress completely undone. Sheldon blinked, the after image of his fantasy gone, replaced by a more responsible Penny who was in the process of helping him remove his suit jacket and tie to place in his dirty clothes hamper.

Sheldon blinked again, willing the temptress Penny back into his mind. His hands would be on her waist then, sliding under the folds of that dress to caress the smooth skin of her hips as she let the dress fall about her ankles.

Sheldon blinked once more, sensible Penny of the real world again in his eye sight as she pulled back his sheets and helped him get situated into bed.

A blink and sensible Penny was gone again, replaced by seductive Penny and all her naked glory. His hands would be on their way up her frame, cupping her breasts as he took a rosy bud into his mouth. She would be softly moaning his name, her hands resting against the nape of his neck as he fondled her shamelessly.

Blink. Sensible Penny was placing a glass of water on his nightstand as well as a couple of aspirin as she asked him if he was comfortable. He felt himself nodding, making Penny comfortable enough to take her leave.

Blink. Seductress Penny was also making her leave, sliding her dress back on before also exiting the room. Sheldon almost called back out to her only to remember that the real Penny, the reasonable Penny had left 5 minutes prior to her seductive, imaginary twin.

Sheldon shook his head drunkenly, wanting to clear his mind and sleep off the fog hanging low in the recesses of his brain. Hopefully he'd be back to his version of normal by the morning.

-/-

Penny sat atop the washing machine her clothes were currently in, a magazine held loosely between her small fingers. Flipping through the pages, Penny couldn't help but think about her professor slash neighbor. Last night had been pleasant, and after a couple of drinks, she found that Doctor Cooper was actually very charming under that condescending, smug persona that he normally wore. By his second Amaretto Sour he had loosened up, genuinely opening himself to her in a way that most friends would. It wasn't until she'd started rambling about her most recent and most damaging relationship that she felt something shift between them.

Suddenly, he wasn't just a kind man who had humored her and come with her to the bar for a couple of drinks. No, he had become a strange, almost unearthly entity that occupied the same space as her own. Something so beautiful and endearing and Penny wasn't sure when it had happened (maybe when she first set eyes on him in that empty classroom? Perhaps when he showed her mercy and began to tutor her? No, maybe it was as recent as last night, when he had smiled at her and told her that perhaps she wasn't entirely useless), but she could feel something break between them causing Sheldon to become something secretly precious to her.

Penny looked up as she saw the man of the hour make his way into the laundry room with his own load of dirty clothing. Penny smiled.

"Hi Sheldon." She said, noticing the way that he paused momentarily as he realized that she was also in the room.

"Hello Penny." He said softly, placing his basket on a nearby table.

"How'd you sleep?" She asked him, her faced scrunched with concern.

Sheldon didn't look up from the washing machine as he answered her.

"Very deeply, actually." He admitted, "However, I seem to be experiencing minor bouts of nausea, bowel distress and an encephalalgia directly associated with loud sounds and intense light."

"That's called a hangover, Sweetie." Penny chuckled as she went back to reading her magazine.

She heard Sheldon make a small sound of acknowledgement as he closed the lid to the washer and repositioned himself to stand in front of the table. Penny could feel Sheldon's gaze on her, causing her to peek over her magazine to stare into those brilliantly blue eyes of his.

"Something on your mind, Sweetie?" She heard herself ask.

Sheldon fidgeted slightly, his mouth falling open only to snap shut again, like a large, lanky trout. Penny sighed lightly as she placed her reading material down and jumped down from the washer, positioning herself in front of her suddenly mute teacher. She had never thought she would see the day when this slender man would actually be rendered speechless, even his most eloquent of useless speeches nowhere to be found.

"Okay, if you're not going to say anything than I guess I'll break the ice." Penny said, "Where are you from?"

Sheldon raised an eyebrow at her in slight confusion. "Come again?"

Penny shrugged, "Since you obviously don't want to tell me what's on your mind, I've decided to fill the awkward silence with useless chit chat. Where are you from?" she repeated, "Like where were you born and raised? Based on that twang that you let slip last night, I'd say you're from somewhere down south. Probably Texas or Louisiana…"

Sheldon shifted slightly, readjusting his laundry basket to sit marginally closer to the edge of the table.

"I was born in East Texas," He admitted, "Raised in the backwoods of Tyler. I moved here to Pasadena in my early twenties."

"I'm from Nebraska myself." Penny supplemented, "I've only been in California for a couple of years. Why'd you move so far from home, Doctor Cooper?"

Sheldon shrugged, a movement that seemed uncharacteristic of the normally self-assured man.

"I had just finished traversing the known world and didn't see any viable opportunities back home. Caltech had noticed my achievements and offered me a very lucrative position out here in Pasadena. I immediately took the offer and was hired on as a Theoretical Physicist. My current occupation as a Physics Professor is a more recent development."

Penny nodded, moving her clothes to the dryer as she asked Sheldon another question.

"Why'd you chose to go from writing research papers to grading research papers?"

Sheldon paused at this. Penny wasn't sure if it was because he himself wasn't sure or if he simply didn't want to discuss the matter any further with her. After a moment of silence, Penny decided to break the awkward atmosphere that had settled between them.

"I'm an actress." She said, eliciting a sideways glance from Sheldon.

"Pardon?"

"I've been asking you what you're all about, I decided I should probably contribute to the conversation as well. I'm an actress." Penny repeated, "When I'm not being a waitress at the Cheesecake Factory."

"I'll bite," Sheldon said, "What sort of acting jobs have you acquired?"

"How kind of you to ask!" Penny said theatrically, "When I first moved here, I was hoping to land commercials and prime time spots on network television. But after audition after audition without any call-backs, I ended up finding my niche in music videos and plays."

Penny moved to begin folding her clothing, fresh out of the dryer while Sheldon gave her an indecipherable look. Penny chuckled as she shook her head and moved her attention to a shirt.

"Not those kinds of music videos," She said, reading Sheldon's mind, "I tend to get calls from more alternative bands. Paper Rival, The Neighbourhood, Twenty One Pilots. Band that aren't really well known."

"And you want to make a career out of that? A career of obscurity, dancing in the background of musical artists no one knows a single tune to?"

Penny shrugged, a look of indifference plastered across her face as she finished up her laundry.

"I enjoy it in the same way that you enjoy reading about atoms and equations. I definitely like it more than you like teaching."

Sheldon cocked his head to the side for seemingly the hundredth time that day.

"What are you inferring?"

"That you hate teaching. You'd rather be holed up in a small office, writing theorems, disproving hypotheses, anything aside from teaching a bunch of undergrads about the possibility of multiple dimensions."

Penny threw a wink in Sheldon's direction as she exited the laundry room, basket firmly under her arm.

"But I'd be lying if I said that I wasn't glad that you'd decided to teach. I'm glad I met you."

-/-

**Author's Note:**

Okay. First off, I want to extend my deepest and sincerest thanks to the reviews and follows and favorites. I really appreciate it more than you can possibility understand.

I don't have a lot to say about this chapter. I really enjoyed writing it, especially the drunk Sheldon scene. I actually zoned out and kind of hallucinated that scene before I wrote it, so I hope you enjoy it as much as I do. Aside from that, there's not a whole lot for me to bring up. If you like the story so far, please feel free to comment, follow, and favorite as you see fit.


	3. Chapter 3

**Title:** The Alternate Universe Paradox  
**Summary:** Penny Cuoco is a lot of awful, terrible, completely true things. But she is not indecisive and more than anything, she wants Doctor Sheldon Lee Cooper, she just doesn't completely comprehend why yet...AU. Shenny  
**Rating:** M  
**Disclaimer:** I do not own Big Bang Theory or the pairings would be Penny and Sheldon/Amy and Leonard, not the other way around.

**Chapter 3 Song **_**Pairing**_  
_"Lurk"_ by The Neighbourhood

Penny's ledger was gushing red, drowning in it, and the gravity of her fascination was beginning to weight on her. Penny wasn't in debt; far from it, actually. She had learned how to be financially responsible in her last disastrous relationship. If there was one thing that her ex-boyfriend was good at, it was making her feel inadequate and irresponsible. She had learned very quickly that the easiest way to avoid his jabbing and cynicism was to grow up and become a reasonable adult. Penny had stockpiled tens of thousands of dollars between waitressing and the gigs she took for music videos and commercials. She'd learned to budget and save and, honestly, she was currently living off of the interest alone, but her most recent endeavors—namely, her most recent obsession—were starting to financially reflect in her accounts.

Penny sighed heavily as she closed her laptop and willed the red numbers from her memory.

She really needed to get a life, to stop this silly dance that she was going through for the sake of sating her over abundant curiosity. She needed to move on and stop worrying so much about why things had gone the way they had for her. Curiosity killed the cat after all. _But everyone knows it was the dog that made the car swerve_, Penny added mentally before catching herself. Why was she trying to convince herself that what she was doing was proper; it was anything but proper, it was borderline unhealthy. She had to make a choice. She had to be honest with herself and stop with this self-mutilation she was subjecting herself to…

_Knockknockknock._ "Penny."

_Knockknockknock_. "Penny."

_Knockknockknock_. "Penny."

Penny sighed as she made her way to the door, flinging it open to reveal her professor looking cross and dressed in a striped thermal, superhero shirt, and khaki pants.

"Yes Sheldon?"

Sheldon sighed dramatically, pursing his lips and holding his large hands tightly in front of him as he spoke sharply.

"When you first acquired this flat, I had made it abundantly clear that any kind of disturbance that you made would not be tolerated. So, I am here to kindly request that you turn off that ratchet that you call music so I can focus on my work."

Penny looked at her teacher with a look of confusion littering her face. Music? She wasn't listening to music…She looked around her apartment quickly, the sound of her album suddenly catching her ear for the first time since she turned it on over 30 minutes prior. She had been so caught up in her own thoughts, she had forgotten that she had turned a record on to calm the chaos raging within her. However, the album was barely above a whisper in her own apartment, so how could Sheldon hear it below her?

"Quick question professor, how could you have possibly heard it a floor below me?"

Sheldon sighed, a patronizing sound that made Penny feel as though she should have already known the answer to her question.

"It is a common fact that I have superior hearing. To me, the volume of that record is reminiscent of the volume of an average conversation. So, turn it off…Please." Sheldon said, the 'please' sounding like an afterthought to the statement.

Penny thought for a moment, curiosity and spontaneity getting the best of her before she walked over to her record player and turned the volume up, earning a scowl from Sheldon standing in her doorway.

"Sure, I'll do that. However, you have to do me a favor." Penny began, "Dance with me and I will gladly turn the music off."

Sheldon sighed for what felt like the umpteenth time since he'd knocked on her door 5 minutes ago.

"Penny, while I subscribe to the "Many Worlds" theory which posits the existence of an infinite number of Sheldons in an infinite number of universes, I assure you that in none of them do I dance."

"Oh, come on!" Penny begged, "Humor me! Just one little dance and the music is gone."

Sheldon scoffed earning a grumpy look from Penny's direction.

"Come on, Sheldon. The world doesn't end because the doctor dances, so dance with me."

Against Sheldon's word, Penny was dragging him into her apartment as the mellow sounds of the record player washed over them. She gently placed his hands on her hips and pulled him close to her body, not caring if he wasn't comfortable with the proximity and intimacy it entailed. Their bodies lightly rocked together as she felt her limbs growing electric, like live wires let loose in a rainstorm. Penny could feel her heart rate hitching as she snuggled closer to Sheldon's chest, her hands sitting lazily against his shoulders, the height difference coming to the forefront as her ear sat directly above his beating heart.

"This is completely ridiculous." She heard Sheldon mutter as he gently pulled her closer to him, completely contradictory to his annoyed sounding declaration.

Penny let her eyes flutter closed as she made a sound of acknowledgement, her hands raking down Sheldon's chest lightly. She heard his heart beat erratically, his breath hitching in his throat making a beautiful baritone rumble in his chest, like a large cat readying a mighty purr. She looked up at him softly, her emerald eyes colliding with his aquamarine and there was something in the way that his pupils dilated as she stared up at him. Something in the way in which his cheeks flushed, in the way that his bright blue eyes and dark hair contrasted so starkly against his pale skin, in the way he fit so snuggly against her and felt under her palms that was so awe-inspiring that she held her breath and blurted out the first thing that came to her mind.

"You're absolutely stunning, Dr. Cooper."

Sheldon seemed to be caught off guard by this declaration and momentarily faltered in his steps before picking up where his steps initially stopped.

"Well, I am flattered, but with an IQ of one hundred and eighty seven and having obtained two doctorates before adolescents, I think it is safe to assume that I am an exquisite example of the human race. As a matter of fact, I consider myself _homo_ _novus_, the first of a superior mutation of the human race meant to…"

Penny cut off Sheldon's tangent lecture, her lips colliding with his in a way that she was sure he would deem unnecessary, inappropriate, and unsanitary, but she would savor in the experience none the less. For a moment, his soft lips were pressed statically against her own, like a warm putty against her mouth. However, she could tell when Sheldon's reasoning had ceased, making him no more than a man responding to a kiss from a beautiful woman when he began to press firmly into her own flesh, his head dipping low to taste the lingering flavor of Dr. Pepper on Penny's tongue.

If she wasn't experiencing it herself, Penny wouldn't have believed it possible for Sheldon to be so well-trained in the art of the "French Kiss," his tongue much more experienced than she would have imagined for a man so terrified of potential contamination and germs. And yet, here he was before her, holding her head in his large hands, slowly digesting her one kiss at a time.

And just as abruptly as it had started, it had stopped, and he was holding her at arm's length, his pupils so large that his eyes looked nearly black in the dim light of her apartment. She could see the beginning of a cold sweat breaking out above his brow, his flesh tinged pink all over, and she was sure that she looked just as disheveled as he. Before Penny could even open her mouth to ask him what was wrong, he was making his way towards her door flinging it open before walking out and closing it swiftly behind himself.

Penny stood stunned and drowning in the silence of her living room, the record that had been playing long ended.

-/-

Sheldon immersed himself in teaching and refused to think about what had happened just a few days prior. He would not let his eidetic memory relive the softness of Miss Cuoco's body pressed against him or the way in which her small hands racked against his body making him break out in light shivers of anticipation. He refused to let his scientific side reason with him, trying to convince him to explore those feelings of pleasure he had experienced in the short time he had been connected to Penny by the mouth.

Dr. Cooper knew how the pleasure center of his brain worked (much in a similar fashion that dogs' brains worked when being trained through positive reinforcement) and he refused to allow himself to become nothing better than a male dog being whipped into submission through treats and head petting. He was _Homo_ _Novus_ and biology be damned! He was better than the average male!

Sheldon stilled as he heard footsteps approach him; he had dismissed class more than 10 minutes ago, and if he was to believe in his natural intuition, he knew who it was that was standing behind him now.

"Doctor Cooper." Penny said softly.

"Miss Cuoco." Sheldon stated as he turned to face her.

"I just want to apologize," She began, leaning on Sheldon's desk and casting her eyes towards the floor. Sheldon couldn't help but admire the view from his position, especially how full her breasts looked leaned over his desk and how pink and glossy her lips looked in the artificial lighting (Shut up primitive brain!).

"For the other day. I live in the realm of impulse and I behave off of it daily. It was inconsiderate of me to throw you in that position without taking into account that being impulsive and randomly attacked may not be your forte. I just…I don't want to ruin our friendship being the kind of woman that I am. So…sorry."

Sheldon bit back the desire to smile at her apology, and instead opted to join his hands in front of him before simply nodding his acknowledgement.

"Thank you, Miss Cuoco. It is not in my usual protocol to show appreciation, but I will make this a one-time exception."

Penny's smile brightened as she looked fully at Sheldon, her eyes twinkling happily. Sheldon's mind began to calculate the probability of her parents having brown eyes as compared to a more rare eye color as well as the probability of any of her siblings having green eyes as well as her gaze grew ever more steady, looking like a beautiful tigress fresh from a successful hunt. Sheldon felt his pants begin to grow slightly uncomfortable as he continued to calculate the figures in his head. It didn't happen often—times when Sheldon would need to relieve himself in a much baser sense—but he knew he would need to today.

It was another 5 minutes before Penny took her leave, bidding Sheldon a good rest of his afternoon. It was another 5 hours after that before Sheldon would find himself alone in his own apartment.

He wasted no time making his way to his bedroom, pulling off his trousers and underwear before seating himself comfortably atop his bed. He closed his eyes quickly, willing forward the image of Penny leaned against his desk, breasts pushed together so tantalizingly. He could image himself behind her, his hands lightly tugging on her long blonde curls, the round expanse of her bottom pressed firmly against him. He would slid into her in that position, her inner walls tight around him before pushing her further down on his desk, exams and research papers fluttering to the floor like leaves off a dying tree. He could almost hear her moaning in his ear.

"**_Yes…right there…harder, Sheldon. Harder._**

He would comply to her of course; he would always bend to her will, they both were aware of that.

He could feel the softness of her hips under his fingertips, feel the tightness of her stomach as her inner walls tightened signaling her impending climax. Just a few more thrusts and Sheldon could feel himself falling off of the cliff face with her, tumbling into a mess of sticky limbs and heavy breathing.

Sheldon opened his eyes, his lower abdomen covered in his release. He stilled as he went to grab a tissue from his nightstand, a low sound catching him off guard. A sound that appeared reminiscent of a cat in heat. A sound indicative of dark bedrooms, throaty moans, and tangled limbs…coming from Penny's apartment…curious…

-/-

"FUCK!" Penny shrieked as Kirk hit her spot with just enough force to make her legs turn to jelly underneath him.

"Ah…Penny…" Kirk moaned, slamming into her again and again with such fervor that Penny was sure she would be feeling it for the next week.

She knew that it was a pathetic attempt at trying to satisfy the burning she had been feeling in her stomach since she had so hastily kissed her professor, but she wasn't a genius, she was just a horny woman and the best she could come up with was rebound sex with the walking, talking Neanderthal Kirk. Penny tried to imagine that it was Sheldon on top of her, his cool chest pressed against her bare back rather than Kirk's, his lips muttering incomprehensibly complex equations for string theory or altruism rather than the dirty things Kirk was possessed to say. The thought of him explaining derivatives was enough to send Penny shooting up into the sun, her skin ablaze in the afterglow of her climax, Kirk not far behind.

Kirk had been gone for about 10 minutes, causing Penny to drift into a light sleep when those tell-tale knocks rang out through her apartment, making her jump. It didn't take her long to throw on her softest robe and answer the door.

"Sheldon, what a pleasant surprise."

Sheldon looked around her apartment curiously, as if looking for something that wasn't there.

"Good evening, Penny." He began, looking over her shoulder towards her bedroom, "I heard some distressing noises and thought it prudent that I check and definitively determine if it was due to some kind of perilous activity."

Penny blushed a brilliant pink, her embarrassment apparent on her features.

"That's really kind of you. I just had a friend over was all. Nothing perilous going on in here!"

"Okay." Sheldon shrugged, seemingly satisfied with her answer before turning and walking away.

Penny watched him intently as he turned the corner down the stairs, her gaze captivated by his mere presence before slowly closing the apartment door and calling Kirk to instruct him to turn around and come back to her place.

-/-

Sheldon knew he was basically running on auto-pilot, his mind distracted by the idea of Penelope Cuoco and the curious invitation he had opened the day before. Sheldon's hand daftly scribbled equations for calculating radioactive decay for radioisotopes, his mouth already reciting the well-known data that his brain regularly refreshed, his mind lingering on the elegant scrawl of the card sitting on his living room table.

_You are cordially invited to the union of Doctor Amy Farrah Fowler and Doctor Leonard Hofstadter at the San Diego Botanic Garden._

Sheldon noted the date enclosed, noticing that it was less than a week away and had to wonder why he'd received the invitation so late, if not at all. He and Dr. Farrah Fowler had ended on fairly amicable terms, their relationship agreement properly notarized, copied, and filed. He was even the individual to inadvertently bring she and his once co-worker together, not that he minded in the slightest. Based off of Sheldon's limited experience in the realm of love and matrimony, he was sure that the whole idea of being invited to the wedding was meant to be an awkward encounter, and yet he somehow had possession of an invitation addressed in his name.

Perhaps they had debated the idea of letting him know of the upcoming nuptials (that would explain why he would have received it so late) and had realized better of thinking that he would be offended by their happiness.

Sheldon glanced at his watch as the bell rang loudly, dismissing his class for the weekend, his mind still wondering how to react to the news when he realized that Penny was still in the process of packing up and heading out the door.

"Miss Cuoco," Sheldon blurted out, stopping her in her tracks, "Would you mind assisting me with something? I seem to be in a bit of a moral dilemma."

In much her typical fashion, Penny's head shot up, a look of interest apparent on her features.

"Oh?" She stated, "A moral dilemma? I happen to be very good at those."

Sheldon scuffed at her playful attitude.

"This is serious."

"Of course it is professor. What's up buttercup?"

Sheldon scuffed yet again at her playful banter deciding to ignore it for the sake of his own sanity.

"I received an invitation to the wedding of the neurobiologist I had previously shared a relationship with and I am not entirely certain as to what the proper protocol is for these types of situations."

"Aw, sweetie." Penny cooed, making her way closer to his desk, "It's always difficult to see someone that you were once very close to move on. I'm sure she wouldn't hold it against you if you declined the invitation."

"No, no, that's not the problem." Sheldon stated matter-of-factly throwing Penny off, "No, the problem is not seeing her get married—I'm, in my own way, completely comfortable with her finding happiness in the mundane—but in social morays of these kinds of events. Is it customary to bring a gift to these gatherings? Am I required to wish them good luck in fertility? I'm not sure what the protocol is here."

Penny placed a hand on her hip, obviously exasperated by his limited contact with the outside world.

"Sheldon, it's just a wedding. You show up, bring a gift like a lamp or engraved wine glasses, tell the bride and groom 'Congratulations,' and go home." She stated, "If it's going to be that confusing I can go with you as your plus one to make sure you don't muck anything up."

With that Penny made her leave of the classroom, muttering under her breath Sheldon's idiocy when it came to the real world.

-/-

**Author's Note**: Hello readers! This is the-WYSIWYG-type with another chapter of the Alternate Universe Paradox. This was hands down my favorite chapter to write, especially the whole dancing scene. I find it a little bit difficult to keep the characters true to themselves when I want them to do very specific things, but I like to imagine I kept them as close to themselves as possible.

Now to me, there's something so...naughty about Sheldon being a person and having sexual triggers, however if you ever watch the unaired/test pilot for TBBT, they actually bring up the fact that Sheldon has a butt fetish (hehehe. Sheldon and butts.). The unaired pilot was almost identical to the pilot that we all know and love aside from the location and some of the characters. It's awful, I won't even lie, but I loved how they made a comment about Sheldon having a pornographic magazine that was specifically about big butts right out the gate. It brings a realness to him that they don't focus on in the official series, which is slightly sad, but I wanted to play on that little nuance with this story (the nuance of him being a real boy).

Another thing, there is a reason for Penny and Sheldon meeting, which will be brought up in the next chapter or 2. There's a slight backstory that preludes to Penny signing up for Sheldon's class, I just haven't decided how I'm going to broach that subject. I'm tempted to have her explain the backstory and then give you guys a prequel type chapter in the **Author's Notes** because I just have this thing against flashbacks. I do want to warn you, the next few chapters are going to read a bit like a landslide; they're going to move very quickly in regards to plot. As I mentioned in the first chapter, I really don't want to make this story long. I want it to be reminiscent of a bunch of interconnected drabbles where the plot isn't dragged out. The next chapter kicked my butt and chapter 5 is kicking my butt even worse because there's just a lot happening all at once, so I want to make sure that you all are aware and prepared.

If you liked the story, please review, fav, alert it. I love updating the story and seeing the number of reviews getting progressively higher, so KEEP IT UP! I'm not writing this for me, I'm writing it for you so definitely let me know what you like and what you don't.

***CHAPTER UPDATE*:** Sorry folks! I got the songs kuffuffled. The song complement for this chapter is "Lurk" by The Neighbourhood. My bad! I will be updating soon though, so thanks for understanding my boo-boo!


	4. Chapter 4

**Title:** The Alternate Universe Paradox  
S**ummary:** Penny Cuoco is a lot of awful, terrible, completely true things. But she is not indecisive and more than anything, she wants Doctor Sheldon Lee Cooper, she just doesn't completely comprehend why yet...AU. Shenny  
**Rating:** M  
**Disclaimer:** I do not own Big Bang Theory or the pairings would be Penny and Sheldon/Amy and Leonard, not the other way around.

**Chapter 4 Song ****_Pairing  
_**"Sting" by The Neighbourhood

Penny sat languidly on the couch in the fitting room of the wedding shop, her head flung back lazily over the back of the neck of the seat. Today was the day that Sheldon would be getting a much more suitable suit for the wedding in just a few days. Penny had yet to meet the bride or groom, not that she really cared one way or the other. As far as she knew, they were very successful, published scientists, much like Sheldon himself and that was okay with her. She had to admit that she did feel a bit like an outsider, the only person that she would be able to cling to during this whole ordeal being Sheldon himself (not that she was completely against the idea of clinging to him in any sense. Shut up brain.)

Sheldon stepped out, the tux officially tuned to his particular physique. Penny couldn't help but undress him with her eyes a little bit as he looked dissatisfied with the choice of attire. From the first time he had saw the offending uniform, he had complained about the price of it considering the fact it was basically only 1 color, black.

"_Not that black is really a color,_" he had crooned, "_since it doesn't consist of any true pigmentation. So, technically, I'm paying a small fortune for no color at all."_

Regardless of how he may have felt, she thought that the choice was to die for. Black slacks, black suit jacket, crisp black shirt, and newly picked ice blue tie. Something about the blue in the tie made his eyes just that much more piercing and hypnotic, and Penny loved it.

"Well, don't you look sharp." Penny teased, knowing Sheldon's discomfort.

"I look like a clown." He grumbled before going back into the changing room to take the restricting suit off.

"No you don't." Penny offered, "I think you look very handsome."

Penny heard a rustle of fabric in the changing room before hearing it come to an abrupt halt, a whispered "You really think so" fluttering to her ears right outside the door.

"Yes." Penny reassured, "Honestly, I think that you look very dapper."

With that, Sheldon made his way from the changing room, fully robed in his typical casual attire and made his way to the register to pay for the overly priced suit.

"I really do appreciate all your assistance Penny." Sheldon stated as they made their way from the shop and back to the apartment.

"No problem sweetie." Penny stated, "That's what friends are for, although friends probably would have been more adamant about not having a gravy boat engraved with 'Please return to Doctor Sheldon Lee Cooper in the event of a marriage annulment or divorce.' But it's your money, I guess."

Sheldon shot her a curious look which Penny echoed back in his direction.

"Problem sweetie?"

"You said we were friends." Sheldon stated.

"Because…we are…aren't we?"

Sheldon thought for a moment before deciding to answer.

"I suppose so. Hm…that's curious. I wonder when that transpired…"

-/-

Sheldon sat next to Penny, his mind curious as to when she had become such a prevalent part of his regular routine. There she was, sitting precariously across the recliner to his left, reading a trashy magazine as he played 3-dimensional chess. She was perfectly at home in his personal space and, to some degree, he supposed the same could be said of him.

When had it happened? He wondered. The first recollection he had of spending any kind of time with her outside of the classroom had been when he had been tutoring her. Perhaps it had begun that night he invited her over for dinner after studying. Or maybe it started when she had taken him out for drinks.

No, she had dug her claws into him much sooner than that. By the time he had taken his first sip of that Amaretto Sour, neigh, by the time he had naively looked into her large green eyes and offered to teach her she had already branded herself into his mind. Like a deadly pathogen slowly dissolving his brain one square centimeter at a time.

Sheldon racked his brain trying to come up with a logical series of events as to how this had come to pass, his hand moving mechanically over the chess board without thinking. He came up blank, the only thing seeming to shed any form of sense on his situation a quote from a book his mother had once enjoyed.

"_It happens accidentally, in a heartbeat, in a single flashing, throbbing moment_."

Sheldon scuffed at the possibility of something so dependent on reason happening so suddenly and abruptly. Even the birth and death of a star wasn't nearly as instantaneous, it was a slow process that took hours, year, millennia to happen and those processes were nothing more than nature. Supernovas did not make a list of pro and cons before bursting in existences, black holes do not feel regret for the light and sound that they devoured. The universe is predetermined and even in its endless routine nothing happens in a heartbeat.

Sheldon looked up sharply aware that he was being watched. Penny's brilliant cat-like eyes bore into him, the stare so focused that he could see the brown seeping in around the irises.

"You okay sweetie?" She asked, "You seem to be a bit…frustrated doesn't seem correct, but I'll go with that."

"Yes, I am fine." Sheldon lied, "Just thinking about the limitless contingencies of the universe in their relative entirety."

"I figured as much." Penny said jokingly, "How about I play you at chess?"

Sheldon scuffed.

"Have you ever played the game before?"

"Yes, actually." Penny admitted, "And supposedly I'm fairly good at it. I play like Bobby Fischer apparently."

"I highly doubt that." Sheldon intoned.

"Well, then," Penny taunted, "You should have no problem beating me."

Sheldon accepted her challenge, resetting the game board, deciding that he'd leave solving this mystery for another day. Perhaps after the wedding when he'd be able to really focus on the problem at hand.  
-/-

The wedding took place on a Friday in the early afternoon heat of September. Penny had outfitted herself in a dress the same shade of Sheldon's tie, hugging her body tightly in a very pleasing silhouette. She had made her way into the garden, fan in hand for the outdoor affair when she was stopped in her tracks. The only thing that seemed to be processing through Penny's mind was in the form of 4 words: "This can't be happening."

When she'd agreed to be Sheldon's date out of her softness to his situation and her own selfish curiosity, she hadn't bothered to ask who's wedding it was. As far as she was concerned, it was for a highly revered and published scientist acquainted with Sheldon (And, to her merit, she wasn't wrong about that). But now, as she stood just slightly down the makeshift aisle laid out in the beautiful San Diego Botanic Garden facing the one person she really would have been more than happy to never see again in her life, she thought that perhaps she should have been nosy and requested to know so she wouldn't be so conflicted at the moment. At the end of the aisle, standing at the alter speaking with an official in all his 5 foot 5 spectacled glory was Leonard Hofstadter, the man she had believed with all her heart a year ago she'd marry and have a long happy life with. The man she had ultimately ran away from with no indication as to her whereabouts or future intentions.

And yet, there he was standing at the alter like some twisted nightmare from the furthest depths of her psyche. In less than a second, his happy façade dropped as his eyes caught hold of her and was quickly replaced with an adulterous longing that Penny really would relish in smacking off of his face.

Penny grabbed Sheldon's wrist roughly, causing him to turn and look at her.

"Penny…"

"Sheldon, is it okay if I sit this one out?" She questioned, turning quickly on her heels without waiting for an answer from Sheldon.

She fled from Leonard like she had over a year ago. She ran and she refused to look back because then she would see reason, she how badly she must have hurt him just disappearing, see how she was ruining his big day and force herself to live through this torture and he did not deserve that kindness from her. She refused to stop until she made her way to the front gate, mothers, fathers, children looking at her with concern. She was sure she still held a look of wild panic on her face and forced herself to calm down and think through this improbable situation.

She was hurt, of course, emotionally seething from his idiotic happiness. She was angry, physically recoiling from his lecherous stare, especially considering that it was his wedding day. She was almost…blissful wasn't the word she was looking for, but it worked and that seemed to be the most worrying aspect out of all the complex emotions she was feeling. Her heart didn't hurt as much as she imagined, the fear wasn't as poignant as she thought it would be; everything she was feeling was coming from nothing more than the surprise she felt at seeing Leonard about to get married after not having had any contact with him in over 10 months.

Penny took a deep breath and let the realization sink in; she was over Doctor Leonard Hofstadter. She wasn't sure when that had happened, but she knew that it was the honest truth. Leonard no longer had any hold over her.  
-/-

When Sheldon found Penny, she was sitting stiffly on a bench by the front gate. Sheldon wasn't very good at emotional cues, but from the look of panic she had flung at him before running off, he would have been pretty dense to not realize that she needed some time alone. So, he provided it for her and took a seat to watch the nuptials. The moment they said their 'I do's and made their way down the aisle as Doctor and Doctor Hofstadter, Sheldon had taken that as his cue to try and find his date.

He approached her slowly, taking a tentative seat next her, his back mimicking the stiffness in her own. He wasn't good at comforting, but for Penny he would try.

"There there," He offered, unsure of what to do with his hands before resolving to place them in his own lap, "Sheldon's here."

"Sorry Sheldon," Penny sighed, "That was really uncool of me to just run out of there like that."

Penny ran a hand through her hair as she let her back relax into a light slouch, so unlike the pristine and formal blue dress she had chosen to wear. She jumped up suddenly, her demeanor shifting abruptly from depressed to enthusiastic. Sheldon could almost feel himself getting whiplash from the dizzying change in emotions she was displaying.

"You know what?" She asked rhetorically, "I don't care too much for weddings and I know you have no social skills. How about we skip out on the reception and, I don't know, go out to eat or see a movie or something?"

Sheldon stared steadily at Penny, all the consequences of living so precariously popping to the forefront of his mind. Yet, the longer he stared into her shining eyes, the more those negative possibilities seemed all the more worth it and soon he was towering over her, nodding his head in agreement as he followed her out the front gate and into the city of San Diego. They decided on a movie and an early dinner, choosing an action flick and following up with some Chinese food before making the 2 hour drive back to Pasadena. The night passed by fairly quickly, and before either of them were aware of it, they were parking next to their apartment complex, exhausted from the day's adventures, yet something bothered Sheldon.

"Penny," He stated in the darkness of her car, "What happened earlier? At the wedding, I mean."

Sheldon heard Penny sigh heavily, not particularly wanting to answer the question, but feeling the need to provide Sheldon an answer none-the-less.

"Sheldon," She began, "Do you remember that story I told you about the scientist I dated?"

"Of course I do. I have an eidetic memory. I remember everything that anyone has ever said to me ever."

Penny let out an exhausted laugh as she continued.

"Well, Leonard Hofstadter was that scientist."

"…So why'd you run off?"

"Isn't it obvious?" Penny gasped, "I'm human and the natural instinct of the typical person is to shy away from the happiness of someone who hurt you. My past with Leonard isn't…smooth. Our relationship didn't end on such good terms, technically our relationship never really ended. So, to see him standing up there, looking like the happy idiot he is…I was surprised and didn't want to be there, so I did what I normally do with Leonard. I ran away."

Sheldon seemed to ponder on her confession, unsure of what to say, her words opening so many other questions that he was curious to learn the answers to. Before he could voice any other questions, she was halfway out of the car, slamming the door behind her before pushing her way into the apartment building. Sheldon followed closely behind her, feeling as though she was trying to run away from him and his prying curiosity and he didn't like the idea of it at all.

"You know what the most beautiful word in the English language is?" Sheldon blurted out, hoping to distract her from her obvious distress over his questioning.

It seemed to do the trick as Penny slowed her pace upon hitting the third floor.

"What?"

"The most beautiful word in the English language. Do you know what it is?"

Penny shrugged, not looking at him.

"Cellar Door." Sheldon stated, causing Penny to freeze in her steps and face him, coincidentally outside his front door.

Her eyes were tinged pink, not from crying, but from the effort of trying not to. So, Sheldon continued to distract her as best he could.

"Not because of the semantics of the word," Sheldon continued, leaning closer to her as if telling her an important secret, "But because of the sounds it makes."

Sheldon could tell she wasn't so much interested in the words he was saying, but the words that he wasn't. What did he really want to say? Where was this going? He had started blurting out the first fact that he knew without thinking and yet, it felt important, like the whole of their relationship going forward rested on what he had to say. So, he needed to make it good because, for reasons beyond him, he couldn't stand the idea of fucking this opportunity up.

"Most linguist agree that the sound the 'l' followed by 'r' and 'd' followed by that long 'o' sound is very similar to the basic symmetry of music. And yet, people always forget that a cellar door is just a pair of doors connecting one space to a cellar. What's so beautiful about that?"

Penny shrugged, a lone tear escaping passed the barrier of her hard resolve. Sheldon unconsciously wiped the tear away, his hand lingering over the soft flesh of her cheek as Penny hiccoughed quietly from her withheld frustration.

"Personally," Sheldon stated, his voice dropping to merely a whisper, "I don't see the beauty of the superficial. The point is, I don't know about what happened between you and Doctor Hofstadter and I genuinely don't care. All I can say is he missed out on something remarkable by pushing you away."

Penny let out a choked laugh as she lightly tapped Sheldon on the cheek.

"Sheldon," She muttered, a stupid smile spread across her face.

"Sheldon…you idiot."

Before Sheldon could respond, she turned and made her way upstairs leaving a thoroughly confused Sheldon Cooper behind her.  
-/-

Author's Note: Hello my lovely reviewers and readers! This is the-WYSIWYG-type again with another chapter of The Alternate Universe Paradox! (YAY!) First off, I want to say thank you to all the people who have reviewed and read this story and everyone who added it to their favorites and alerts! I can not tell you how much it means to me to see how much you like this story so far.

The second order of business is this: I am having surgery on the 7th of October (pre-op on the 2nd of October) which is just around the corner. Hopefully, since I will be on bed rest for a minimum of a week after the surgery I will be typing like crazy and hopefully have all the chapters finished by mid-October when I have my first post-op appointment. Which means, that after my surgery, as long as everything goes according to plan, you will be getting much more regular updates than what I've been able to do lately. There's nothing to worry about, I am medically fine, my Obstetrician suspects that I have endometriosis and the only way to diagnosis it is to have diagnostic surgery. It's going to be an outpatient procedure, so I'll be going home the same day and my mum has volunteered to stay with me for the recovery period since my boyfriend is currently gone for military duty. So, it should be pretty fun and I'm optimistic. :)

Finally, I want to say that this chapter kicked my butt and if you feel like a lot is going on at one time, that's because there is. Lawl. My mother use to say, "Good things happen one at a time, but bad things happen all at once." So, I kind of wanted to play that card with the story; Penny and Sheldon are having a good time and then Penny's past just comes slapping her in the face, completely catching her unaware, and then things just kind of spiral very rapidly. To me, with my own personal experiences, that's life. Life likes to let you think you're in control before coming back and saying "You're not as in control of everything as you think you are." Everything will be explained soon.

I'm hoping to be done editing chapter 5 by my pre-op appointment and done writing chapter 6 by my surgery date, so lets just keep our fingers crossed on that. Aside from that, I hope you like this chapter (because I loved writing it even though it made me want to pull my hair out multiple times) and please feel free to review, favorite, and alert it.


	5. Chapter 5

**Title:** The Alternate Universe Paradox  
**Summary:** Penny Cuoco is a lot of awful, terrible, completely true things. But she is not indecisive and more than anything, she wants Doctor Sheldon Lee Cooper, she just doesn't completely comprehend why yet...AU. Shenny  
**Rating:** M  
**Disclaimer:** I do not own Big Bang Theory or the pairings would be Penny and Sheldon/Amy and Leonard, not the other way around.

**Chapter 5 Song Pairing  
**"Night After Night" by Laura Marling (with a close second chose of "What He Wrote" also by Laura Marling)

Penny peeked between her spread fingers, looking around the room that was so familiar not too long ago. She knew the script to this day, had stored the memory of it within the dustiest confines of her psych and swore to never visit it again.

And yet, here she was.

She remembered the time, the date, and the place like a recycled set from an old sitcom. All the books on the shelves documenting theorems and published works on one side of the room and comic books along the other were lined in alphabetical order, just how he liked it. The smell of antiseptic was sharp against her nose, stuck in the fibers of the hairs like a pristine hospital room (he never cared for her messiness and was allergic to practically everything and—perhaps out of spite—she had begun cleaning with bleach and ammonia hoping he'd regret his own pickiness. She wasn't sure if he actually appreciated the sterility of her cleaning or was just as stubborn as herself, and she'd never know now.). In the kitchen sat a now cold dinner she had cooked—filets with mashed potatoes and lightly fried green beans—along with a nearly empty bottle of red wine. Penny had given up drinking a few years back, only drinking on very rare occasion, and today was perhaps the most necessary break in her sobriety yet.

Penny blearily looked to the front door, her mind focusing on every line, every wrinkle of Leonard's form as he made his way in, throwing his keys into the bowl by the door and bag to the floor. He looked so happy (damn him), so smug in his superiority that Penny felt she needed to take a long swig of alcohol to keep from smacking him in the face.

_You can improvise_, she thought. _Play this scene out the way it should have been played originally_.

Penny shook her head in thought. No, she had to play this by the book, like the good actress she was. She had to keep her rage alive to function and reading her memorized lines was the only way she could do that.

Leonard stopped halfway between her and the door, taking in the sight of her with an almost empty glass of wine and realized instantaneously that there was something amiss.

"Hey," He started, slowly making his way toward her, "Is everything alright? What happened?"

Penny was silent for a long moment (like she had done a year ago) before answering.

"Seven thirty, Leonard." Penny stated slowly, stretching out each word to make him shift uncomfortably.

"We were supposed to be having dinner at seven thirty. Do you know what time it is right now?"

She took the shiftiness of his eyes and wringing of his hands as an admission of guilt, getting louder as she continued to berate him.

"It is half passed ten. Three hours! You are three hours late to our anniversary dinner…I'm assuming you have a clever excuse for it."

"I was tied up at work." He provided lamely.

"By now, I would hope that if you were going to lie to me, you would at least attempt to do a better job at it than that."

Penny felt surprisingly serene in this memory, much different to how she had felt that particular day. Soon, they'd be in the middle of a shouting match causing Leonard to storm out and her to sit on the couch alone, yet again, too exhausted to even cry over the end of her relationship. It was approaching quickly, the trigger words dancing across the back of her tongue, struggling to get out into the open. _In due time_…

"I'm not lying!" Leonard said, obviously louder than he was planning on by the surprised look that came across his own face.

Penny set her glass down with a satisfying clank, before addressing her (ex-) boyfriend again.

"Who is she?" Penny asked softly.

"Is it someone I know? Is she smarter than me? Prettier?"

Leonard staggered lightly by her implication.

"There is no one else! You're being paranoid, Penny."

Penny sighed, throwing her head back for a moment before standing up and making her way to Doctor Hofstadter. She caught him off guard, capturing his lips in the briefest of kisses before pulling away and looking him in the eye.

"I'm not being paranoid," Penny said, rubbing her fingers across her lips.

"I could feel it in that kiss. I can just about taste her on your tongue, you liar!"

She made to storm away, originally wanting to run to the bedroom, pack up a bag and leave, but now (just like then) he grabbed hold of her by her arm, turning her around to keep the confrontation alive.

"What are you talking about?" He spat, "Have you been watching too many daytime soap operas while waiting for casting calls? You can't tell anything from kissing someone!"

"You just love rubbing it in, don't you?" Penny shrieked, yanking her arm away from him and backing up 2 paces.

"How I'm so inferior to you! How nothing I do or know has any merit because I don't have a degree! How I'm wasting my life trying to be an actress, picking up two bit parts for you to use as further ammo against me!"

"Maybe if you did have even a minor educational background in deductive reasoning, you wouldn't think a kiss was suitable evidence to proclaim infidelity!"

Penny stalled for just a moment as his insult hit home, only furthering her rage and before she knew it, it had slipped. The simple statement had come tumbling out in all her blind fury; a little, insignificant sentence that destroyed everything.

"And maybe if you were a fraction of a real man, you wouldn't have to insult my intelligence to feel important!"

Everything fell silent as Leonard looked at her and she back at him, her words like a live grenade that had just exploded and lodged shrapnel deep within them both. And no matter how much she wanted to, she could never rearrange that small pipe bomb and place the pin back in. She had obliterated them, the evidence lingering in the pregnant silence between the two of them before Leonard scuffed, turned his back to her and made his way back to the door.

"Leonard, wait!" Penny pleaded.

Why did she plead? Why couldn't she see that the 2 of them together was a volatile mixture, like potassium and water, doomed to explode upon contact and burn everything around them?

He stopped momentarily, his back rigid as he picked his bag back up and fished his keys back out of the bowl.

"I didn't mean it."

Leonard looked at her for a sad moment, before addressing her.

"My mother once wrote a book about how conversing while experiencing intense emotions can help you understand a person's true intentions. I only ever read a few chapters of it, but she once stated, 'people are never more their true selves than when they are angry'."

Penny was silent as Leonard opened the front door, and made his way out.

"Don't wait up for me."

-/-

Penny was drained, her bandaged hand held close to her chest as she looked at the stains setting into the carpet of their apartment. After Leonard's departure, instead of falling into a fit of crying hysteria, she had gone on a rampage, throwing the still full plates of food against the wall, her almost empty wine glass on the floor, and ransacked the bookshelves and upturned the furniture. As a child growing up on a farm in Nebraska, she had been taught to take her anger out on a couple of cans lined up on a fence with a bee-bee gun, but she had no cans and no guns in southern California, just Rachel Ray dishware, Lazy Boys furniture, and Physics textbooks, so she took her rage out on those. At some point, she had cut up her hand, and it was only once the wound started to sting that she felt she had done enough damage on the apartment.

So, she sat on the disheveled couch, her legs against her chest as she stared at a blank point on the wall. It was late (or early, depending on your perspective) and she could feel the sleepiness settling into her bones as the adrenaline wore off. However, she couldn't stay there in what was once "their" apartment.

Stretching, Penny made her way into the bedroom, packing up a bag of all her essentials and a few sets of clothes, unsure if she would ever come back to get anything else. In her mind, it was all just "stuff" and "stuff" was replaceable. On the way out the door, Penny's eye caught a manuscript buried under a few other textbooks and journals littered across the floor, its white cover sticking out like a sore thumb through the layers of discarded items across the carpet. As Penny examined the manuscript, she noticed it to be a rough copy, a recently completed compilation of works between Leonard and a Doctor Sheldon Cooper. There was nothing memorable or interesting about the item to Penny's eyes, but the title stuck out to her and she thought it only fair that she take it along with her as a sick sort of memorabilia for her troubles.

Making her way to the front door, Penny scribbled a small note for Leonard before throwing it in the bowl for him to read once he decided to show back up.

_Sorry about the mess_, she wrote.

_I've decided to leave and I don't think I'll be coming back. We were never going to work out anyway._

-/-

Penny was transfix by the manuscript in her hands. Initially, she had resolved to burn it or scrap it, not knowing why she had even taken it in the first place. But as the days went by, her hotel room becoming more and more familiar, it began to leer at her, taunt her with its curiosity and by the 10th day, she had resigned herself to her hotel bed and began to skim it.

She could immediately tell which portions had been written and/or dictated by Leonard by the overall superior tone of his theorems and explanations. Most of the mathematics and science of the essay was a mystery to her, flying far above her head, but she understood the basics of it and, by default, the bare basis of it. It was a collaborative essay pointing out the possibilities of multiple worlds, an infinite number of parallel universes just outside the visible spectrum of our own by Doctor Sheldon Cooper and the theorems that could debunk that theory presented as a counterargument by Doctor Leonard Hofstadter. But she didn't care about Leonard's ideas on the subject (she had enough of Leonard's ideas on subjects), it was the portion written by Doctor Cooper that caught her ravage interest.

An infinite number of her, each one slightly different; a Penny that was born a man, a Penny that decided to finish school, a Penny that died young, a Penny that never moved to California, a Penny that had made it big, the possibilities were endless. And just as the possibilities of an infinite number of shades of herself living just beyond the membrane of their spacial existence was a possibility, there had to also be an infinite number of Leonards; a Leonard that wasn't a genius, a Leonard that was kind and sincere, a Leonard that was taller and less damaged. Perhaps there was even an Earth out there, a single abnormality where they met and dated and fell in love and it worked.

The idea both frightened and exhilarated Penny; a universe where they had worked.

It was a consuming idea and Penny had an addictive personality and before she knew how it had happened, she was wondering what the possibility was of all of the circumstances that had brought her and Leonard together in this universe replicating in another with just a minor tweak to make them more compatible. What would be the odds that (for instance) Earth-12,372 Penny had made all the exact same decisions that she had. Been at that exact same bus stop at the same time she was. Been run into by a hurrying Leonard who clumsily spilled his coffee on her favorite shirt while on his way to a lecture the same she had. It had to be astronomical if not completely improbable. And yet she couldn't shake the thought from her mind.

It was like she had watched a star being born for the first time and was consumed by its awe-inspiring beauty and terrifying power. Suddenly, it felt like all the synapses in her brain were firing at once and she had so many questions and ideas and thoughts happening simultaneously that she felt like she was drowning in her curiosity.

She had to know the possibility of it all, the probability of it all and she had to know it now and she knew who to ask; Doctor Sheldon Lee Cooper.

-/-

It had taken Penny a couple months to figure out where Doctor Cooper worked and another couple months before she was able to register for his class, so she had decided it would be best to further dive into studying the subject of string theory on her own. She wasn't very bright, but Penny was smart enough to be able to halfway understand the plethora of information that Doctor Cooper presented in the multitude of published works he had across the continent. And suddenly Penny wasn't so much interested in the subject as she was interested in the brains behind the idea.

She had never met Sheldon and had only heard about him maybe once before while Leonard was collaborating with him (probably for the essay she had stolen) and even then, all Leonard would allude to was that he was a lab accident away from becoming a mad scientist/super villain. But one thing she could tell in everything she read that he had published, was that he loved physics. He loved the challenge of it, the complexity of it and it bled through in every word he wrote and every equation he balanced. She could feel it oozing off of every scientific journal he was featured in, could almost feel it seep into her fingers like a contact poison whenever she read more about his work.

Penny was a lot of awful, terrible, absolutely true things, but she was not indecisive. And she knew from the moment that she had signed that application for his class what she wanted. Sure, she still wanted him to crunch the numbers, wanted to use him like her own version of Wikipedia to sate her almost painful, newfound ache for knowledge, but she also knew, for reasons that were beyond her, that she wanted Doctor Sheldon Lee Cooper. Even if just to see if he was just as passionate about other aspects of his life that weren't physics related.

-/-

Hello all! This is the-WYSIWYG-type with another update of The Alternate Universe Paradox! (Yay!) I was originally going to post this chapter with chapter 6 once it was done, but Chapter 6 is taking a little while and I figured I'd go ahead and give you guys this chapter to eat up while I work on finishing and editing Chapter 6 (which will hopefully be in the next week while I'm on bed rest).

So, I love talking about the chapters and what my mindset was when I wrote them so you guys kind of understand why certain things happened. This chapter was definitely more of a filler. The reason I even wrote this fanfiction was because of this chapter. I had a very vivid vision of Penny and Leonard getting into a huge argument and before Leonard walks away, I imagined him making a snarky comment about Penny's intelligence and alluding to the fact that he's been kind of seeing Amy behind her back (of course she doesn't know Amy or anything) and to really grind the point further, he throws this manuscript on table that was written by both him and Sheldon and basically tells Penny that if she can't understand the ideas behind it, then she shouldn't be surprised if he does leave her for someone with a higher IQ. That was the initial scenario I had in my head that really made me want to write this fanfiction. By the time I got to this chapter, I had realized that Leonard behaving like that would be REALLY out of character and completely rewrote the script to be more believable. Which led to this chapter!

Fun fact: my mother worked for the police department and federal BOP for over 20 years and one thing that she use to tell me all the time when I would ask her opinion about people was pretty much this: "You never really know a person until you have a conversation with them when they're in emotional distress." As I got older, she simplified it to: "People are never more their true selves than when they're angry." Which I don't know if their is any validity to that, but that seems like something Leonard's mother would say, so I threw it in there.

Anyway, I loved this chapter. It was by far the easiest chapter to write because I've been thinking about it since chapter one. I definitely wanted to play on Penny's addictive personality trait and how a Eureka moment would happen for her. I just love the idea of little innocuous things shaping people into who they become and for some weird reason I loved the idea of Penny grabbing the manuscript as an afterthought, almost as one last middle-finger to Leonard, and how that one decision lead up to everything else. Something about the idea of those small decisions making all the difference in how we progress is beautiful to me and I enjoy sitting and making a list of all the little choices that bring you to the present.

But enough of my rambling. I hope you enjoyed the chapter as much as I did. Please review with any questions, comment, or concerns. Please feel free to fav/follow if the feeling overcomes you and I will be updating (hopefully) very soon. So keep a look out for that. :)


	6. Chapter 6

**Title:** The Alternate Universe Paradox  
**Summary:** Penny Cuoco is a lot of awful, terrible, completely true things. But she is not indecisive and more than anything, she wants Doctor Sheldon Lee Cooper, she just doesn't completely comprehend why yet...AU. Shenny  
**Rating:** M  
**Disclaimer:** I do not own Big Bang Theory or the pairings would be Penny and Sheldon/Amy and Leonard, not the other way around.

**Chapter 6 Song ****_Pairing_**  
_"Take Me to Church"_ by Hozier

**_**LEMON WARNING**_**: This chapter contains a nice, juicy lemon. Please read and review at your own discretion. Thank you for your cooperation.

Sheldon sat at his desk nervously, unconsciously looking up at the ceiling every few minutes. He hadn't seen Penny since the night of the wedding over a week ago; she hadn't attended any of his classes, hadn't made a whisper of noise in her apartment above him or seen her during their scheduled laundry days. Sheldon didn't want to admit it, but from the first day he'd realized she was missing from his lecture room he'd been nervous, worried even.

He wasn't accustomed to caring about other people, much less the opposite sex, and the idea that he had said or done something inappropriate that had driven her off felt like physical torture for reasons that perplexed his advanced thinking. The first possibility to cross his mind was that she had withdrawn from his course, being intensely insulted or (dare he think) disgusted by his actions from that night. After all, it wasn't too out of character for Penelope Cuoco to make brash decisions first and follow logic second. So, after she had missed his lecture for the third day in a row, he had marched straight to the campus admissions desk and demanded to know if she had pulled out of his course. And to his relief she was still listed as an active student. But that relief was quickly engulfed by worry.

Why wasn't she coming in? Why hadn't he heard from her? Had he done something wrong? Said something out of place? Acted incorrectly?

Sheldon raked his eidetic memory trying to find a flaw in his behavior and nothing immediately stood out. Nothing but the last thing she had said to him.

"_Sheldon…Sheldon, you idiot._"

What had he done? He must have done something. Had his caress across her cheek been unwanted? Had the way he had leaned in closer to her caused her distress? What had he done? What had he said! Whatever it was, he had done it with good intentions because he liked Penny, he craved her attention like a rescued stray. He wasn't sure why, but he was attracted to her. He couldn't recollect when it had happened or why, but he knew for a fact that he was attracted to her. He didn't want to be a slave to his baser instincts, but he couldn't deny his biology or anatomy.

He cared for Penny, even lusted for her occasionally and right now he was desperate to see her. He imagined this was what addicts felt when they were detoxing; a crippling emptiness followed by the desire for one more fix to stave off the shakes before quitting for good. He was trying to move on with his routines in the manner he had before meeting Penny, but every day of not seeing her was starting to feel more and more like a chore and he had to admit that he couldn't focus properly without her anymore.

Doctor Sheldon Cooper sighed before resigning to make his way to her apartment to sort all of this out for himself instead of theorizing.

-/-

Penny sat numbly in her disheveled bed, that damned manuscript feeling like a lead brick between her fingers. She had yet to dispose of it feeling a twinge of sadness at the idea of burning it, shredding it, or even just plain throwing it out. She'd nearly forgotten about it over the past few weeks and only once she'd seen Leonard had she remembered what she was even doing in Pasadena. And that was when the guilt had set in.

She was here to use Sheldon, to conquer him like a damn mountain.

She'd lost sight of that from the moment he had insulted her that first day. It was then that she had decided to just stick the course out and hopefully destroy her curiosity in him and the subject. But he was entrancing, mesmerizing even and suddenly she just desired him more. Sure, he was an insufferable know-it-all and he constantly mocked and talked down to her, but he was passionate on paper and in person and his drive and desire shone in his eyes when he was excited like freshly burst supernovas in the depths of space.

Penny sighed as she looked at the paper, the only physical proof of her fascination with Doctor Sheldon Lee Cooper, PhD. She had to dispose of it and put the thoughts threatening to destroy her comfortable relationship with the lanky theoretical physicist out of her mind. Penny was pulled from her thoughts as she heard the telltale knocks at her front door.

She pulled herself from the bed and made her way to door, the manuscript still held in her hands. It wasn't until she had halfway opened the door that she had realized her error before throwing the offending object behind the couch. Penny wasn't able to stop the soft smile that ran across her face upon seeing Sheldon standing at her door with a small grocery bag of items, looking slightly sheepish in his typical casual attire.

"Hey sweetie. What do you have there?"

Sheldon fidgeted as he held the bag out for Penny to take.

"A box of tissues, cold and flu medicine, some Vicks Vapor Rub, and other items typical of minor illness."

Penny threw Sheldon an odd look.

"What makes you think I'm sick?"

"Well," Sheldon began matter-of-factly, "You haven't attended class in eight days, you've made no attempt that I'm aware of to leave your apartment, and I haven't heard an utterance of activity from you in that time. Considering that you are still actively enrolled at Caltech, I figured it wasn't a simple matter of dropping out and based on the accumulation of cobwebs and loose debris on your car, I also deduced that you haven't made an attempt to even leave the building. So, the obvious conclusion was illness."

Penny turned scarlet red at his deduction. 8 days. She had unconsciously sulked for 8 days. She had meant to take a day or 2 to get herself sorted out and somehow managed to take over a week.

"Sheldon," Penny began, placing the bag of medicine on the living room table.

"I am SO sorry. Seeing Leonard brought up all kinds of…stuff that I wasn't ready to deal with. I didn't mean to miss class or make you worry. I'll be back in class first thing tomorrow. Promise."

Sheldon stood in the doorway, a light smile on his face.

"I'm glad that you're alright." He began, "And I've been told that it is a non-optional social convention between friends to ask what is wrong."

Penny rolled her eyes playfully in Sheldon's direction before answering him.

"That's sweet and all, but it's nothing that you can help me with."

"That's highly unlikely. I have an IQ of one hundred eighty-seven, two doctorates, and have been published in magazines and scientific journals across the US and a few select countries. If anyone could deduce a logical solution to your problem, it would be me."

Penny sighed as she tried to figure out what to do. She could lie to Sheldon, tell him a mock situation to help her with. Or she could convince him that whatever problem she had wasn't worth his brain power (which would probably work very well because it would stroke his insatiable ego. But he may find her niceties suspicious, so that option wasn't a particularly good one). Or she could simply rip the bandage and lay everything out on the table, taking extra care not to mention any emotional turmoil she was having in regards to how she felt towards him.

After a moment, Penny motioned for Sheldon to take a seat on her couch as she made her way behind it to pick up his old manuscript. She plopped down on the cushion next to Sheldon and took a deep breath before closing her eyes and willing the words out of her mouth.

"What would you say if I told you that us meeting wasn't coincidence?"

"Well, if I am to believe quantum mechanics which are inherently deterministic, then I would have to say that coincidence doesn't exist." Sheldon shot back quickly, "Why do you ask?"

Penny sighed heavily, willing her hands to bring forth that paper bound article of her fascination and place it on the table in front of Sheldon. She calmly waited for him to pick the battered journal up and examine it. Her stomach flipped in her chest as she watched the confusion in his eyes flicker to recognition and then change to a color of intrigue. She was trying with all of her available willpower to form her thoughts into coherent speech and attempt to not come across as some stalkeresque creep, but the way those brilliant blues were staring transfixed at her, curious as to how she had come to possess such an intimate article of unpublished scientific knowledge, she found her mind going blank and her mouth throwing out the first thoughts to possess her.

"I've been fascinated by you for a while now...From the moment I took that manuscript from that damn apartment when I left Leonard, I knew I was in trouble. I've read that thing from cover to cover, every single word backwards and forwards even the ones that didn't make sense to me. Something about your tenacity, your absolute faith in the possibilities...I sought you out. I don't have a major because I don't want one, I don't need one. I was so blindly certain that if I met you, you'd be able to answer every question I've ever had. Be able to erase any of my doubts.

"I am selfish by nature, Doctor Cooper; I am the worst type of person."

Sheldon appeared stunned by Penny's open and honest confession, at a complete loss for words as to what to say. She held her breath as he placed the journal back on the table, letting his fingers linger atop the familiar words for a long moment before turning to face Penny fully.

"I don't seem to understand, Penny..."

Penelope sighed, running a tired hard across her face and closed her eyes as she tried to recompose her thoughts.

"Leonard was cheating on me with the woman he ended up marrying, that much I'm certain of. But, when we got into that last, relationship ending confrontation I snapped. I destroyed our apartment and yet that rough draft somehow survived. I took it with me when I left and, out of vague curiosity, I read it. It...it was life changing. Not Leonard's labored and contrived portion, but yours." Penny couldn't help but notice the boyish smirk that flickered across Sheldon's face at her words.

"I'd never thought of the possibility of multiple worlds and multiple outcomes. I'd never given the progression of my own life much thought, always thinking of things in terms of cause and effect, a disconnected collection of "if" and "then". I never thought of the possibility of everything I've done as a whole being a purely unique occurrence. I became obsessed with the science of it and was determined to know the probability of it all which led me to you. I signed up for your class desperate to quench my new found thirst for knowledge, to prove that I was important mathematically and scientifically. To prove that I mattered...

"At some point, I lost sight of that." Penny further confessed, "We became closer than student and teacher, we became friends and all the selfish reasons that I sought you out were put on the back burner, forgotten. And then I saw Leonard and it all came flooding back...Just because I forgot that I was trying to be selfish doesn't make me any less selfish..."

"You're not selfish, Penelope." Sheldon blurted out without thinking, "You're a lot of things; insufferable, stubborn, and aggressive. However, you aren't selfish from what I've been shown."

Penny smiled at Sheldon's words, touched by his uncharacteristic flattery. She could feel herself warming up to him, her body unconsciously scooting imperceptibly closer to him with every word spoken. He was doing it again, hypnotizing her with his baritone voice and piercing eyes. She knew she was losing her internal battle to keep her hands to herself, yet Penny didn't care. All that seemed to be coursing through her mind was how badly she wanted to place her hand on his chest, curl her fingers in the soft hairs along the nape of his neck and overpower him...

"Sheldon," Penny started, her voice thick with her desire to taste him.

"What is the probability of this happening again? Of my life starting over and ending up in this exact same position whether its in this universe or another, hypothetically speaking?"

"Well," Sheldon began, his body arching closer to Penny on the couch and his eyes turning a dangerous shade of midnight.

"If we are to take every choice you've every made, compile ever moment of 'coincidence' that's ever occurred to you that led you to this specific life path that you're on now and quantify it with a physical number, the rough estimate of your life replicating in the exact same fashion again would be an one in ten to the twenty-seventh power probability, based on the limited information that I have about your past endeavors. That is an extremely rough estimate, purely dependent on—"

Doctor Cooper was cut short in his explanation as Penny pressed herself against him, soft lips crashing against his own sharply. Almost too soon, Penny pulled away, throwing a hand to her mouth in shock, seemingly surprised by her own actions.

"Penny..." Sheldon moaned out, his voice heavy with longing.

"I'm so sorry Sheldon. I wasn't thinking—"

It was then Penny's turn to be interrupted by Sheldon as he pulled her flush against him. For a moment, Penny was dazed by Sheldon's forcefulness and eagerness to kiss her. It was one thing for her to attack him, but another thing entirely for him to attack her. Once she was able to overcome the completely out of character behavior of Sheldon Lee Cooper's lips moving in time with her own, she immediately snapped into Big Ol' 5 territory, unashamedly moving to straddle Sheldon's tall frame as she raked her fingertips through his short dark hair. She could feel the telltale bulge of an erection forming against her belly as his slender hands moved from her face to feather against the smooth expanse of skin along her hips. After a few moments, they realized that breathing was still a necessity as they parted for air swallowing big gulps of it to help steady their rapidly beating hearts.

For a few tense seconds they stared at one another, their pupils so full and dark that the color of their eyes looked almost black under the bright lights in Penny's apartment. It was as if they were testing the waters, debating mutely between one another if they should divulge in the carnal desires they were feeling at that moment. It was the feel of Penny's soft fingers across the cottony stubble of Sheldon's chin that broke the tenseness in the air, effectively unlocking something primal in Sheldon as he tightened Penny's legs around his torso before lifting them both up, clearing the living room table with his free arm and roughly laying Penny on her back across the wooden surface. Penny mewled loudly as Sheldon ravished her lips and neck, her hands making quick work of the button and zipper of his pants. His member sprang to attention as she pushed his pants down, exposing all his magnificence to her eager eyes.

Perhaps it was the look of hunger in her eyes or the shut down of Sheldon's logical brain, but within 5 seconds of releasing Sheldon from the confines of his trousers, Penny was being flipped around, her ass forced into the air as Sheldon pulled her pajama shorts down to fall in a heap around her ankles. Penny growled in satisfaction as he rubbed his hardness across the wetness of her sex before plunging into her swiftly.

Penny loved the sounds that Sheldon was making, loved the pressure of his chest against her back, the feel of his flexed arms under her shaking fingers. She could almost imagine it, watching them like a fly on the wall as Sheldon drilled into her and she screamed in pleasure at the sensation. It was a glorious feeling having him fill her to the brim and a little extra as he shakily whispered her name over and over like a prayer on his lips. She was getting close, just a little bit further, a little bit deeper and she'd be plunging over that cliff, tumbling in a tangle of sweaty limbs and matted hair with only the ghost image of Sheldon to comfort her as she fell.

"Oh Sheldon...fuck...Sheldon...Right there, right there..."

She could feel the tell-tale signs of his own climax coming quickly, feel the shaking overtaking his limbs as his breathing became more and more labored against the shell of her ear.

"Penny...oh Penny..."

It only took a moment for Penny to reach her climax, shrieking as the orgasm hit her harder than any orgasm had before, the colors of the room crashing together, the sounds of their love making bouncing around her fogged brain like a copper pot. She shook roughly as Sheldon followed close behind, pulling out just in time to cum across her bared bottom.

Penny felt her legs fall haggardly to the floor, her sweat drenched hair plastered to her forehead as she rested her head across the nice cool wood of the table. She heard the couch creak as Sheldon fell back against it, his breathing ragged after their vigorous act. Penny dared a look in his direction, immediately wishing that she had a camera to remember the look on his face forever. She wanted to sear the image of him in her mind, from the way his dark hair stuck out across the top of his head to the intensity of his icy blue eyes against the flushed flesh of his face.

"Sheldon, that was...wow..." Penny said lamely, pushing some hair from her face.

"That was unexpectedly enjoyable." Sheldon admitted after a long moment, closing his eyes as he threw his head back.

"Yeah." Penny sighed out.

For a moment Penny felt content, wanting to take a nice warm shower before crawling back into bed, dragging Sheldon along with her for some entertainment. However, after a moment Penny began to worry.

She just fucked her professor and all that ever spelled out was S-H-I-T.

-/-

**A/N:**

Hello, once again! It is I, the-WYSIWYG-type, back once more with another chapter of The Alternate Universe Paradox! Yay! First off, I want to say thank you to everyone who has Favorited, reviewed, the works. I know I haven't updated in a bit and I apologize for that. I have no excuse. To anyone who is wondering, my surgery was a success; it was textbook from going in, to having scar tissue removed, to the recovery. I recovered in record time (a little over a week), I healed marvelously, and I feel fantastic! On to my personal notes about this chapter!

I originally wrote this chapter while I was on bed-rest and hit a brick wall at the Sheldon thinking Penny was sick part. While I was going through writer's block on this chapter, my old computer decided to crap out on me. I was able to salvage everything and move it to my new laptop, but it didn't help with the writer's block at all. Honestly, this chapter could have been written better. I'm not particularly crazy about it, especially the lemon portion. I love the idea of a feral Sheldon sort of just taking what he wants, and in regards to that imagery, I think I succeeded, but I feel like I rushed it. There will be more lemons in the future (hopefully) and I plan on those being a little more descriptive and well written, but I'm my worse critic.

Also, fun fact about the figure Sheldon threw out there ("..._one in ten to the twenty-seventh power probability_..."). I studied a lot of information about George Price and his paper on how altruism is a survival trait and connected to natural selection simply because it's a very compelling paper. There was a small blurb about him on the Science Channel in which they went over every aspect of his life from before he came up with that equation and wrote the essay to when he became a devote Christian and ultimately tried to disprove his paper which resulted in his suicide. That specific figure was the probability that George Price actually calculated in regards to the coincidences of all the occurrences in his life basically leading him to where his life was. So, essentially the exact thing Penny is asking Sheldon about. I love the idea of Penny being aroused by Sheldon's knowledge as much as being irritated by it and that seemed like the perfect catalyst for them bumping uglies in my mind.

I will be finishing this story up in the next couple of chapters and, so far, I'm loving chapter 7, so hopefully you guys will love it too when I upload it probably within the next week or so. Aside from that, I hope you enjoyed this chapter. Please review, favorite, follow, whatever possesses you and I hope you all have a marvelous Thanksgiving (if you live in the US and celebrate it).


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